text: In organic chemistry, a carbonyl group characterizes the following types of compounds:
  Other organic carbonyls are urea and the carbamates, the derivatives of acyl chlorides chloroformates and phosgene, carbonate esters, thioesters, lactones, lactams, hydroxamates, and isocyanates. Examples of inorganic carbonyl compounds are carbon dioxide and carbonyl sulfide.
  A special group of carbonyl compounds are dicarbonyl compounds, which can exhibit special properties.